Fig. 5. Time taken to increase extracellular [K⁺] by 1 mmol l^–1 above basal values after superfusion with ouabain during normoxia, after 2 h of anoxia, during normoxia in the presence of theophylline and after 2 h of anoxia in the presence of theophylline. Values are means + S.E.M., N=5. *Statistically different from the value for the corresponding normoxic group (P<0.05).